1. Field of the Invention
This invention relates to a recirculating gutter for swimming pools of the overflow type, and which provides for reduced water turbulence.
2. Description of the Prior Art
The use of overflow gutters for recirculating water from swimming pools has been known for many years. Typically such gutters include a gutter conduit with a front wall over the top of which dirty water flows, which provides for skimming the top surface of the pool water to a predetermined depth. The water overflowing the front wall typically flows through an open grate around the perimeter of the pool, and into the gutter conduit from which it flows by gravity into a converter and then into a tank from which it is removed by a pump, and passed through a filter or filters. The filtered clean water may pass through a heater, and then to a return water conduit or header pipe, which has nipples or other connections for returning the clean water to the pool. Examples of such systems are shown in the U.S. Pat. Nos. 2,932,397 to Ogden; 3,432,867 Whitten; and 4,080,670 Van den Broek. While such systems operate satisfactorily in their intended function of removing or skimming dirty water from a pool, filtering the water and returning the clean water to the pool, there are many applications where other considerations are present.
With the ever increasing popularity of swimming as a sport, and with improvements in swimming techniques, it has become apparent in pools used in competition such as the Olympics, that the skimming and return of clean water to such pools creates turbulence which has varied and noticeable effects on swimmers in the different lanes in the pool. In order to compensate for this turbulence, it has been necessary in many instances to shut off the filters during pool use, resulting in less than desirable sanitary conditions and violating various city and state health codes in effect for public swimming pools. Studies of the causes of turbulence have led to the conclusion that turbulence results from various obstacles to the smooth flow of water, both in the gutter conduit and in the clean water return system. The dirty water which overflows into the gutter, and is therefore "skimmed" from the pool water surface, faces a variety of obstacles in its journey around the gutter to the converter. There is no head or pressure in the gutter conduit water flow imposed by a pump. The flow is by gravity and the free surface has a distinct gradient. Then, efficient drainage is promoted by constructing a gutter channel with minimum resistance to the free flow of water, this will be achieved by placing elliptical shields described below around the injection nipples. The prior art nipples are often oriented so that the water flow into the pool is directed against the pool walls, which with the tremendous volume of water returned resulted in mineral deposits along the walls as well as a bounce back turbulent effect on the water. The prior art injection nipples often had a restriction at their exit into the pool, which resulted in noticeable turbulence at the water entry locations, and for a 75 foot by 175 foot pool, would have provided 125 such separate nozzles.
In terms that a swimmer would use, what is desired is a "fast pool" wherein the swimmer notices no turbulence, and therefore no interference with his swimming efforts, so that the lane position in which he or she swims does not affect performance. The gutter system of my invention provides such a "fast pool", as well as providing the health advantages obtained from an overflow recirculating gutter system.